Semiconductor component having a dopant region formed by a dopant composed of an oxygen/vacancy complex

ABSTRACT

A semiconductor component includes a semiconductor body having a first side and a second side opposite the first side. In the semiconductor body, a dopant region is formed by a dopant composed of an oxygen complex. The dopant region extends over a section L having a length of at least 10 μm along a direction from the first side to the second side. The dopant region has an oxygen concentration in a range of 1×10 17  cm −3  to 5×10 17  cm −3  over the section L.

PRIORITY CLAIM

This application is a Divisional of U.S. application Ser. No.13/613,985, filed on 13 Sep. 2012, which in turn claims priority toGerman Patent Application No. 10 2011 113 549.2, filed on 15 Sep. 2011,the content of said applications incorporated herein by reference intheir entirety.

BACKGROUND

Dopant regions within a semiconductor body are required in allsemiconductor components. Dopant regions which extend deep into thesemiconductor body or are situated deep in the semiconductor body arerequired for some applications. A field stop zone of an IGBT (insulatedgate bipolar transistor) or of a diode serves as an example of this. Theproduction of such a field stop zone, i.e. of a zone of increased dopingdeep in the semiconductor body, is described, for example, in DE 10 2004047 749 A1.

A field stop zone is usually produced by diffusion, particularly in thecase of semiconductor wafers having a relatively small diameter 6inches) or thicknesses of above 200 μm. In this case, by way of example,for the production of an n-type dopant region as a field stop zone,either phosphorus or selenium atoms are indiffused into thesemiconductor body. This usually results in doping profiles having aGaussian distribution and a penetration depth into the semiconductorbody of typically between 1 μm and 30 μm.

Field stop zones, which have to be produced at relatively lowtemperatures on account of the semiconductor wafer thickness and thewafer diameter, are usually produced by proton implantation. In thiscase, temperatures in the range of 400° C. are usually sufficient forproducing the desired n-doped field stop zones. What is disadvantageousin this case, however, is that the resulting doping profile of the fieldstop zone has a considerable undulation. This can lead e.g. to anundesirable change in the gradient in the current and voltage profileduring the turn-off operation of e.g. an IGBT. However, the undulationof the doping profile can in some cases adversely affect the softness ofthe turn-off operation.

SUMMARY

Exemplary embodiments of the invention relate to a semiconductorcomponent comprising an extensive dopant region in a semiconductor body,which has a relatively small variation of the dopant concentration. Inparticular, exemplary embodiments relate to power semiconductorcomponents comprising such a dopant region. Furthermore, exemplaryembodiments of the invention relate to a method for producing such adopant region in a semiconductor body.

It is an object of the invention to provide a semiconductor componentcomprising a dopant region, in particular a field stop zone, having asmall variation of the dopant concentration. Moreover, the intention isto provide a method that makes it possible to produce such a dopantregion in the semiconductor body.

Exemplary embodiments of the invention are explained in greater detailbelow. However, the invention is not restricted to the embodimentsspecifically described, but rather can be suitably modified and altered.It lies within the scope of the invention to combine individual featuresand feature combinations of one embodiment with features and featurecombinations of another embodiment in a suitable manner, in order toarrive at further embodiments according to the invention.

In one embodiment, a semiconductor component comprises a semiconductorbody having a first side and a second side situated opposite the firstside, and a dopant region in the semiconductor body. In this case, thedopant region is formed by a dopant composed of an oxygen/vacancycomplex over a section L having a length of at least 10 μm along adirection from the first side to the second side and has an oxygenconcentration in the range of 1×10¹⁷ cm⁻³ to 5×10¹⁷ cm⁻³ over thesection L. In a further embodiment, the dopant region has an oxygenconcentration in the range of 2×10¹⁷ cm⁻³ to 5×10¹⁷ cm⁻³ over thesection L. In yet another embodiment, the dopant region has an oxygenconcentration in the range of 3×10¹⁷ cm⁻³ to 5×10¹⁷ cm⁻³ over thesection L.

The specific oxygen concentration in the dopant region has the effectthat dopants formed by an oxygen/vacancy complex can form. In this case,an oxygen/vacancy complex should be understood to mean a structure thatcomprises, inter alia, oxygen as a constituent without the oxygen inthis case forming a chemical bond with other constituents of thecomplex. By virtue of the fact that the specific oxygen concentrationextends over a section L, dopant formation can occur uniformly over thesection L on account of the formation of oxygen/vacancy complexes. It isthus possible to provide a dopant region having a small variation of thedopant concentration. By way of example, the dopant region can have adopant concentration that varies along the section L by maximally afactor of 15, furthermore for example by a factor of 10 and once againfor example by a factor of 3.

One embodiment of the invention provides for the semiconductor body tobe formed at least partly from a Czochralski semiconductor material andpreferably from a magnetic Czochralski material. A Czochralskisemiconductor material is a semiconductor material which is pulled froma melt according to the Czochralski method and which can be boughtcost-effectively as a mass-produced product. In the case of magneticCzochralski material, the oxygen concentration is reduced in a targetedmanner by an external magnetic field being applied during the crystalgrowth.

In a further embodiment, the semiconductor body is formed at leastpartly from a float zone semiconductor material. A float zonesemiconductor material is distinguished by the fact that a semiconductormaterial is briefly melted and then solidified again as a singlecrystal. A float zone semiconductor material has a very high purity.

In yet another embodiment, the semiconductor body comprises asemiconductor material epitaxial layer. The semiconductor materialepitaxial layer can be produced on a monocrystalline substrate byarrangement of semiconductor material atoms from the gas phase onto thecrystal lattice of the substrate. Through targeted control of the gascomposition, it is possible to alter the epitaxial layer with regard toits composition in a desired manner.

In one exemplary embodiment, the semiconductor body has a basic dopingwith a basic dopant concentration, and the dopant region has a dopantconcentration higher than the basic dopant concentration.

It is a further exemplary embodiment if the dopant is a thermal donorformed e.g. from a hydrogen-oxygen-lattice vacancy complex.

One embodiment of the invention is a power semiconductor component,comprising a semiconductor body having a first side and a second sidesituated opposite the first side. A first electrode is arranged at thefirst side and a second electrode is arranged at the second side of thesemiconductor body. A pn junction in the semiconductor body is situatedbetween the first electrode and the second electrode and a dopant regionin the semiconductor body, which is formed by a dopant composed of anoxygen/vacancy complex over a section L having a length of at least 10μm along a direction from the first side to the second side, has anoxygen concentration in the range of 1×10¹⁷ cm⁻³ to 5×10¹⁷ cm⁻³ over thesection L.

In this case, a power semiconductor component should be understood tomean a semiconductor component in which voltages of more than 20 V,usually more than 500 V, are present between the first and secondelectrodes. In this case, a power semiconductor component isdistinguished by the fact that a high voltage of more than 20 V presentin the reverse direction across the pn junction does not lead to thedestruction of the semiconductor component. In one exemplary embodiment,such a power semiconductor component comprises a so-called drift zonebetween the pn junction and one of the electrodes, in which drift zone aspace charge zone can form over a wide section in order to avoid fieldstrengths within the semiconductor body. In this case, the drift zonehas a dopant concentration that is low relative to other dopant regionsoccurring in the semiconductor body. A power semiconductor component canbe, for example, a diode, a MOSFET (metal oxide semiconductor fieldeffect transistor) or an IGBT.

In one embodiment of such a power semiconductor component, thesemiconductor body has a basic doping with a basic dopant concentration,and the dopant region has a dopant concentration higher than the basicdopant concentration. By way of example, in this case, a drift zonepresent in the semiconductor body can have the basic dopantconcentration and the dopant region can be a field stop zone arranged inthe drift zone and having a higher doping. The field stop zone preventsthe punch-through of the electric field strength in the drift zone asfar as the electrode.

For the so-called softness of the turn-off operation of the powersemiconductor component, it can be advantageous if the dopant region hasa dopant concentration that varies along the section L between adjacentdoping maxima and doping minima for example by maximally a factor of 15,furthermore, for example, less than by a factor of 10 and once again,for example less than by a factor of 3. The fall in the dopingconcentration at the end of the section L toward the basic doping is nottaken into account in the specification of these factors. This means, inparticular, that the ratio of the height of adjacent doping peaks todirectly adjacent doping minima varies by less than a factor of 15 or 10or 3.

It is one exemplary embodiment of a method according to the inventionfor producing a dopant region in a semiconductor body if a semiconductorbody having a first side and a second side situated opposite the firstside is provided, wherein in the semiconductor body at least one partialregion is formed over a section L of at least 10 μm in a direction fromthe first side to the second side, the at least one partial regionhaving an oxygen concentration in the range of 1×10¹⁷ cm⁻³ to 5×10¹⁷cm⁻³. In the course of heat treating at least the partial region in atemperature range of between 350° C. and 450° C., a dopant regioncomprising a dopant composed of an oxygen/vacancy complex formed in thepartial region over the section L.

In one embodiment, the partial region is formed by setting the oxygensupply during the crystal growth of the semiconductor body in aCzochralski method.

In another embodiment, the partial region is formed by setting theoxygen supply from the gas phase during an epitaxial deposition of thesemiconductor body on a semiconductor substrate.

In a further embodiment, the partial region is formed by outdiffusion ofoxygen from a substrate into an epitaxial layer deposited thereon.

A further exemplary embodiment provides for the partial region to beformed by indiffusion of oxygen via the first side or via the secondside into the semiconductor body.

It is yet another exemplary embodiment if the partial region is formedby implantation of oxygen into the semiconductor body.

One development of the method provides for the oxygen concentration inthe partial region to vary along the section L. By way of example, itcan be advantageous if the oxygen concentration decreases in a directiontoward the first side. This can lead to an effective smoothing of thedopant profile within the dopant region.

One exemplary embodiment provides for the semiconductor body to bethinned before the formation of the partial region at the second side.

Furthermore, one embodiment of the method provides for hydrogen to beintroduced at least into the partial region before the heat treatment.This can firstly accelerate the diffusion of oxygen atoms and/orfacilitate dopant formation. By way of example, the hydrogen isintroduced by implantation of hydrogen ions. Moreover, the implantationor indiffusion can be effected with at least two different implantationenergies, such that hydrogen accumulations are produced at differentdepths in the partial region. In conjunction with the increased oxygenconcentration in the partial region this can lead to the formation ofdopant concentration profiles in the partial region which vary spatiallyto a lesser extent than in a region having an oxygen concentration thatis significantly less than 1×10¹⁷ cm⁻³.

In one exemplary embodiment of the method, the heat treatment iseffected over a time period of 30 minutes to 5 hours and preferablybetween 1 hour and 4 hours. The annealing temperature is typically inthe range of between 350° C. and 450° C. It is thereby possible toachieve, for example, a relatively weakly varying dopant distribution ofthe dopant concentration in the dopant region over the section L.

In one development of the method, the dopant region is predominantlyformed by thermal donors formed from a hydrogen-oxygen-lattice vacancycomplex. In one exemplary embodiment, for this purpose in thesemiconductor body, lattice vacancies are produced at least in thepartial region before the heat treatment.

A further embodiment of the method provides for the dopant region toacquire a dopant concentration that varies at least along the section Lbetween adjacent doping maxima and doping minima by maximally a factorof 15, preferably 10 and particularly preferably 3.

Those skilled in the art will recognize additional features andadvantages upon reading the following detailed description, and uponviewing the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The components in the figures are not necessarily to scale, insteademphasis being placed upon illustrating the principles of the invention.Moreover, in the figures, like reference numerals designatecorresponding parts. In the drawings:

FIG. 1 shows a semiconductor component comprising a dopant region in asemiconductor body;

FIG. 2 shows a power semiconductor component comprising electrodes onopposite sides of a semiconductor body and comprising a dopant region inthe semiconductor body;

FIG. 3 shows a dopant profile in a semiconductor body of a semiconductorcomponent;

FIG. 4, which includes FIG. 4a and FIG. 4b , shows a method forproducing a dopant region in a semiconductor body;

FIG. 5 shows the introduction of hydrogen into a partial region of asemiconductor body; and

FIG. 6 shows a dopant profile in a semiconductor body of a semiconductorcomponent.

DETAILED DESCRIPTION

Before the exemplary embodiments of the present invention are explainedin greater detail below with reference to the figures, it is pointed outthat identical elements in the figures are provided with the same orsimilar reference signs and that a repeated description of theseelements is omitted. Furthermore, the figures are not necessarily trueto scale, rather the main emphasis is on elucidating the basicprinciple.

FIG. 1 illustrates a semiconductor component 10 comprising asemiconductor body 11 having a first side 12 and a second side 13situated opposite the first side 12. The semiconductor component 10 canbe a diode or an IGBT, for example, wherein the possible embodiments ofthe invention are not restricted to these two types of semiconductorcomponent.

In the exemplary embodiment shown, the semiconductor body 11 can beformed at least partly from either a Czochralski semiconductor materialor magnetic Czochralski semiconductor material, or a float zonesemiconductor material or a semiconductor material epitaxial layer. Thesemiconductor body 11 is generally present as a semiconductor wafer,from which one or more semiconductor components are then produced. Thesemiconductor wafer can have a wafer diameter which, in the presentcase, is for example>200 mm. The diameter can be 300 mm, for example.The thickness of the semiconductor body 11 is normally approximately 750μm, but can also be smaller. By way of example, the semiconductor bodythickness can be less than 200 μm. FIG. 1 furthermore illustrates adopant region 14 in the semiconductor body 11. The dopant region 14 isformed by a dopant composed of an oxygen/vacancy complex. The dopant canbe formed, for example, from a hydrogen-oxygen-lattice vacancy complex.The dopant region 14 extends over a section L having a length of atleast 10 μm along a direction X from the first side 12 to the secondside 13. In this case, the dopant region 14 has an oxygen concentrationin the range of 1×10¹⁷ cm⁻³ to 5×10¹⁷ cm⁻³ over the section L. In oneembodiment, the oxygen concentration can be in a range of 2×10¹⁷ cm⁻³ to5×10¹⁷ cm⁻³. In a further embodiment, the oxygen concentration can evenjust lie in a range of 3×10¹⁷ cm⁻³ to 5×10¹⁷ cm⁻³.

The semiconductor body 11 has a basic doping with a basic dopantconcentration. The dopant region 14 has a dopant concentration higherthan the basic dopant concentration. In a development relative to theexemplary embodiment from FIG. 1, the semiconductor component is a powersemiconductor component.

FIG. 2 shows an exemplary embodiment of a power semiconductor component20, comprising a semiconductor body 21 having a first side 22 and asecond side 23 situated opposite the first side 22. A first electrode 24is mounted at the first side 22 of the semiconductor body 21. At thesecond side 23, a second electrode 25 is mounted on the semiconductorbody 21. In the semiconductor body 21, a pn junction 26 is situatedbetween the first electrode 24 and the second electrode 25. The pnjunction 26 is formed between a p-doped partial region of thesemiconductor body 21 and an n-doped partial region of the semiconductorbody 21. Furthermore, a dopant region 27 is situated in thesemiconductor body 21. The dopant region 27 is formed by a dopantcomposed of an oxygen/vacancy complex. The dopant can be formed, forexample, from a hydrogen-oxygen-lattice vacancy complex. The dopantregion 27 extends over a section L having a length of at least 10 μmalong a direction X from the first side 22 to the second side 23. Thedopant region 27 has an oxygen concentration in the range of 1×10¹⁷ cm⁻³to 5×10¹⁷ cm⁻³ over the section L.

The semiconductor body 21 of the power semiconductor component 20normally has a basic doping with a basic dopant concentration. The basicdoping is often used in a drift zone or base zone 28 of the powersemiconductor component 20. The drift zone 28 lies between the pnjunction 26 and the dopant region 27. The dopant region 27 can be afield stop zone, for example.

FIG. 3 illustrates an example of a dopant profile within a semiconductorbody having a dopant region. The semiconductor body has a basic dopingwith a basic dopant concentration 30. In this case, the basic dopantconcentration 30 is in the range of 1×10¹³ cm⁻³ to 1×10¹⁴ cm⁻³. Thebasic dopant concentration can be used for forming a drift zone or basezone within a power semiconductor component. The semiconductor bodyfurthermore has the dopant region of a section L, wherein the dopantsare predominantly formed by an oxygen/vacancy complex and the dopantconcentration is above the basic dopant concentration. This higherdopant concentration has values in the range of 1×10¹⁴ cm⁻³ to 1×10¹⁵cm⁻³. Moreover, the higher dopant concentration varies over the sectionL maximally by a factor of 3.

FIG. 6 shows a further example of a dopant profile within asemiconductor body having a dopant region. FIG. 6 shows a dopantconcentration in a dopant region in which the basic dopant concentrationhas a high undulation, with maxima 91 and minima 92. In the case of anoxygen content, or in the case of an oxygen concentration of 1×10¹⁷ cm⁻³to 5×10¹⁷ cm⁻³, the undulation of the maxima 93 and minima 94 decreasesgreatly. With an oxygen concentration of 1×10¹⁷ cm⁻³ to 5×10¹⁷ cm⁻³, thedoping concentration varies in such a way that a doping concentrationmaximum and an adjacent doping concentration minimum differ maximally bya factor of 15, preferably by a factor of maximally 10.

FIG. 4a illustrates a first intermediate result of a method forproducing a dopant region in a semiconductor body. For this purpose, asemiconductor body 11 having a first side 12 and a second side 13situated opposite the first side 12 is provided. In the semiconductorbody 11, at least one partial region 15 is formed over a section L of atleast 10 μm in a direction X from the first side 12 to the second side13. The at least one partial region 15 has an oxygen concentration inthe range of 1×10¹⁷ cm⁻³ to 5×10¹⁷ cm⁻³. The partial region 15 can beformed, for example, during the crystal growth of the semiconductor body11. Thus, the formation of the partial region 15 can be formed forexample in a Czochralski method, e.g. a magnetic Czochralski method. Inanother example, the partial region 15 can also be formed by setting theoxygen supply from the gas phase during an epitaxial deposition of thesemiconductor body 11 on a semiconductor substrate. Furthermore, thepartial region 15 can be formed by outdiffusion of oxygen from asubstrate into an epitaxial layer deposited thereon. An epitaxial layercan be used e.g. for producing drift zones or base zones in powersemiconductor components. In a further example, the partial region 15can be formed by indiffusion of oxygen via the first side 12 or via thesecond side 13 into the semiconductor body 11. In the case ofindiffusion via the first side 12, e.g. during the processing of powersemiconductor components the oxygen should be indiffused into thesemiconductor body 11 already before a polishing of the first side 12 ofthe semiconductor body 11, in order to ensure that the oxygen atoms areindiffused as deeply as possible. In yet another example, the partialregion 15 can be formed by implantation of oxygen into the semiconductorbody 11, wherein suitable indiffusion steps are usually carried outafter the implantation.

Depending on the way in which the oxygen is introduced, it is possibleto set the oxygen concentration in the partial region 15 along thesection L in such a way that the oxygen concentration in the partialregion 15 decreases along the section L. In this case, the oxygenconcentration can also be set such that it decreases in a directiontoward the first side 12. An embodiment that is not illustrated providesfor the semiconductor body 11 to be thinned before the formation of thepartial region 15 at the second side 13. This can play an important partfor example during the indiffusion of the oxygen via the second side 13into the semiconductor body 11.

FIG. 4b illustrates the semiconductor body 11, in which, by means ofheat treatment 40 (represented as arrows in FIG. 4b ) at least of thepartial region 15 in a temperature range of between 350° C. and 450° C.,a dopant region 14 is formed by means of an oxygen/vacancy complexhaving a doping effect in the partial region 15 over the section L. Inthis case, hydrogen H can be introduced at least into the partial region15 before the heat treatment 40. This is shown in FIG. 5. The hydrogencan be introduced, for example, by implantation of hydrogen ions. Inthis case, the implantation can also be effected with at least twodifferent implantation energies. This gives rise, in the partial region15, to hydrogen accumulations and also greatly increased vacancydensities at different depths. If, by way of example, the dopants in thedopant region 14 are formed from a hydrogen-oxygen-lattice vacancycomplex, so-called thermal donors, the hydrogen accumulation atdifferent depths of the partial region 15 makes it possible to achieve avery homogeneous distribution of the dopants in the dopant region 14over the section L. Furthermore, lattice vacancies or additional latticevacancies can be produced in the semiconductor body 11 before the heattreatment 40 at least in the partial region 15 preferably by means ofhydrogen implantation. This can foster e.g. the formation ofhydrogen-oxygen-lattice vacancy complexes.

Spatially relative terms such as “under”, “below”, “lower”, “over”,“upper” and the like, are used for ease of description to explain thepositioning of one element relative to a second element. These terms areintended to encompass different orientations of the device in additionto different orientations than those depicted in the figures. Further,terms such as “first”, “second”, and the like, are also used to describevarious elements, regions, sections, etc. and are also not intended tobe limiting. Like terms refer to like elements throughout thedescription.

As used herein, the terms “having”, “containing”, “including”,“comprising” and the like are open ended terms that indicate thepresence of stated elements or features, but do not preclude additionalelements or features. The articles “a”, “an” and “the” are intended toinclude the plural as well as the singular, unless the context clearlyindicates otherwise.

With the above range of variations and applications in mind, it shouldbe understood that the present invention is not limited by the foregoingdescription, nor is it limited by the accompanying drawings. Instead,the present invention is limited only by the following claims and theirlegal equivalents.

What is claimed is:
 1. A semiconductor component, comprising: asemiconductor body having a first side and a second side opposite thefirst side; and a dopant region in the semiconductor body, formed withan oxygen/vacancy complex acting as donor over a section L having alength of at least 10 μm along a direction from the first side to thesecond side, wherein the dopant region has an oxygen concentration in arange of 1×10¹⁷ cm⁻³ to 5×10¹⁷ cm⁻³ over the section L, wherein thesemiconductor body has a basic doping with a basic dopant concentrationand the dopant region has a dopant concentration higher than the basicdopant concentration.
 2. The semiconductor component of claim 1, whereinthe semiconductor body is formed at least partly from a Czochralskisemiconductor material or a magnetic Czochralski semiconductor material.3. The semiconductor component of claim 1, wherein the semiconductorbody is formed at least partly from a float zone semiconductor material.4. The semiconductor component of claim 1, wherein the semiconductorbody comprises a semiconductor material epitaxial layer.
 5. Thesemiconductor component of claim 1, wherein the dopant region has anoxygen concentration in a range of 2×1017 cm-3 to 5×1017 cm-3.
 6. Thesemiconductor component of claim 1, wherein the dopant region has anoxygen concentration in a range of 3×1017 cm-3 to 5×1017 cm-3.
 7. Thesemiconductor component of claim 1, wherein the oxygen/vacancy complexacting as donor is formed from a hydrogen-oxygen-lattice vacancycomplex.
 8. The semiconductor component of claim 1, wherein the dopantregion has a donor concentration which varies along the section Lbetween an adjacent donor concentration maximum and a donorconcentration minimum by a factor of 15 or less.
 9. The semiconductorcomponent of claim 1, wherein the oxygen concentration decreases in adirection toward the first side.
 10. The semiconductor component ofclaim 1, wherein the oxygen concentration decreases along the section L.11. A power semiconductor component, comprising: a semiconductor bodyhaving a first side and a second side opposite the first side; a firstelectrode at the first side; a second electrode at the second side; a pnjunction in the semiconductor body, the pn junction being situatedbetween the first electrode and the second electrode; and a dopantregion in the semiconductor body, formed by a dopant composed of anoxygen/vacancy complex over a section L having a length of at least 10μm along a direction from the first side to the second side, wherein thedopant region has an oxygen concentration in a range of 1×10¹⁷ cm⁻³ to5×10¹⁷ cm⁻³ over the section L, wherein the semiconductor body has abasic doping with a basic dopant concentration and the dopant region hasa dopant concentration higher than the basic dopant concentration. 12.The power semiconductor component of claim 11, wherein the dopant isformed from a hydrogen-oxygen-lattice vacancy complex.
 13. The powersemiconductor component of claim 11, wherein the dopant region has adopant concentration which varies along the section L between anadjacent doping concentration maximum and a doping concentration minimumby a factor of 15 or less.
 14. The power semiconductor component ofclaim 11, wherein the oxygen concentration decreases in a directiontoward the first side.
 15. The power semiconductor component of claim11, wherein the oxygen concentration decreases along the section L. 16.A semiconductor component, comprising: a semiconductor body having afirst side and a second side opposite the first side; and a dopantregion in the semiconductor body, formed with an oxygen/vacancy complexacting as donor over a section L having a length of at least 10 μm alonga direction from the first side to the second side, wherein the dopantregion has an oxygen concentration in a range of 1×10¹⁷ cm⁻³ to 5×10¹⁷cm⁻³ over the section L, wherein the dopant region has a donorconcentration which varies along the section L between an adjacent donorconcentration maximum and a donor concentration minimum by a factor of15 or less.
 17. The semiconductor component of claim 16, furthercomprising: a first electrode at the first side of the semiconductorbody; a second electrode at the second side of the semiconductor body;and a pn junction in the semiconductor body, the pn junction beingsituated between the first electrode and the second electrode.